1991 5mt broken gear and viscous center differential. Look familiar to anyone?

[DeCheapo]

First a little DeCheapo history. Plain and simple, I am cheap out of necessity. I have owned nothing but "discarded" Subarus since mid '80s when I bought a '79 4WD wagon which had been overheated, and after I replaced the head gaskets was able to squeeze 150K of relatively trouble free service out of it before rust rendered it too frail to jack up and change the tires.

 

It was replaced by a '78 of the same type that I originally bought as a “donor” but decided it was much better than my driver and ended up getting about the same service out of it until it too succumbed to rust.

 

Then c. 1993 I made the jump way up to an ’86 4WD wagon which gave me 3 years and another 100K (almost 250K on the odometer) of service before it met with a culvert that nearly removed the left front suspension. Darn.

 

Other than CV joints, ball joints, and rust those vehicles were very reliable. Especially considering the fact that they weren’t coddled.

 

Finally, the one in question; a ’91 Legacy L AWD wagon. It too was discarded (as totaled) and came with a salvage title and 146K on the odometer. At about 190K third gear let go. An exploratory showed that this gear is a three piece weldment consisting of the gear itself with a short snout machined on it, a slinger which fits over the snout, and then the synchro cone with splines. This is held together by what looked like an electron beam weld in the seam between the snout’s O.D. and the synchro cone’s I.D. Or at least it used to be. The weld broke and the gear and synchro couldn't transmit power. I vee’d it out, MIG welded it and got another 5K before it failed again. I repeated the repair and got about the same service. Third time, I drilled (10) 3/32 holes in the seam and inserted short pieces of music wire and welded it again, sealing in the music wire “keys”. No more problem with third gear.

 

Now at 283K I have a new problem. The viscous center differential has locked up solid causing severe binding in the drive train during turns on hard surfaces. Rather than risk shattering a CV joint, my (temporary?) solution has been remove the rear section of the drive shaft and drive it as FWD.

 

Now for the questions.

1) Has anyone else had either of these failures in the later Subarus?

2) Do the later 5MT’s have the same welded design for third gear?

3) Does Subaru even offer 4WD or have they gone strictly AWD?

 

And now that you know what I mean by cheap, here’s why I ask those questions.

 

1) With the exception of rusting away, my earlier Subarus were mechanically more reliable, but the luxury and performance of the Legacy sure was nice. On the other hand, as the old saying goes “pretty is as pretty does”. It is my belief that reliability is foremost, with economy, performance, and luxury following in that order. As far as style, let form follow function.

 

2) It is my opinion that even if you sent a vehicle to the compactor, you should be able to jackhammer these parts out of the cube and re-use them. The only way they should fail is by lack of lubrication or a bazillion miles of use. But to be fair I don’t know what abuse the car went through with its first owner although it didn’t show signs of neglect or abuse other than a minor crunch to the front end.

 

3a) I preferred the old 4WD to AWD. Many will say that 4WD won’t help you stop any better than 2WD but disregarding vehicles with ABS, I disagree. Many a time I’ve been tiptoeing my way down steep, icy, paved roads where even the slightest application of brakes would cause you to go faster or lose directional control when traction breaks. Even backing off the throttle too much would be disastrous. With good old 4WD, the moment I feel traction break I can lock it in, forcing front and rear axles to turn at the same speed and by gently controlling the throttle I can make tire speed match the ground speed and pick up traction again, restoring directional stability, provided I haven’t let it get too far out of control. And it also seems to balance the braking action between front and rear once traction is re-established provided I don't get heavy footed on the pedal. The viscous coupled center differential in the ’91 never gave me that level of control. In fact, there were times it seemed to initiate instability under those same conditions.

 

3b) Another reason I prefer the old time 4WD is that it gives you more options if something fails. One time out in the boonies, I had a front CV joint shatter its shell. Thankfully, the inner race ripping around on the end of the axle didn’t eat the brake line, but it was close. I happened to find a piece of rod to knock the roll pin out of the inner joint and removed the axle from the transmission. With that done, I simply locked it into 4WD and drove on the rear axle. No tow bill and only fifteen minutes late. It would have only been five minutes if I had my custom made roll pin driver and a real hammer. In fact, I drove it that way for a couple of weeks while I scrounged up another axle. The ’91 and its viscous coupling would never allow that!

 

I doubt that I’ll be fixing the center differential. Not only am I cheap, I’m also getting a bit older and tired. Just like the ’91. It wears me out just thinking about those three 18+ hour days I put in on third gear and especially the stress of having to make the family vehicle ready to go the next morning.

 

I would really like to stay with Subaru but if they have forgotten their old motto of "Inexpensive....and built to stay that way.", then it might be time to change. I don't say that to scare Subaru because a "bottom feeder" like me isn't really a customer. On the other hand, I've "sold" a few new Subarus to friends and acquaintances who see how (relatively) reliable they have been for me.

 

If you have taken the time to read all of this, and especially if you can answer any questions to help guide my decisions, then many thanks for your time.

[low_suby_wagon]

I have a 92 wagon. Its 5mt and FWD not AWD or 4WD. You can always get a tranny like mine and put it on. They are cheap in local junkyards. I am very cheap too, and see nothing wrong driving the car the way it is. I have had plenty of 4x4's that I have disconnected the driveshaft on due to differential problems. Best of luck! As you will find many people on here who say, fix once, fix it right!

[Aczwild]

http://legacygt.com/forums/showthread.php?t=23082